Researchers were able to prove that the use of pesticides is directly related to the spread of parasitic diseases. This could affect millions of people a year.
Scientists at the University of California, Berkeley have found that the use of pesticides and other agrochemicals can accelerate the transmission of schistosomiasis while disrupting the ecological balance in the aquatic environment that prevents infection.
Schistosomiasis is caused by parasitic worms that develop and multiply inside freshwater snails and are transmitted by contact with contaminated water. This infection can lead to liver and kidney damage, and it affects millions of people every year.
A study published in the journal Lancet Planetary Health showed that agrochemicals can enhance the transmission of schistosome worms in several ways: by directly affecting the survival of the parasite in the water, destroying aquatic predators that feed on snails that carry the parasite, and by changing the composition of algae in the water, which are The main food source for snails.
“We already knew that building dams and expanding irrigation networks increased the spread of schistosomiasis in low-income settings, disrupting freshwater ecosystems. But we were shocked at how easily we were able to prove the link between pollution and increased transmission of schistosomiasis”, the researchers noted.
Scientists additionally studied a thousand studies and found 144 experiments that link the concentration of agrochemicals with the components of the schistosome life cycle. They then incorporated this data into a mathematical model that captures the transmission dynamics of the parasite. The model estimates the concentration of agrochemicals after application in agricultural fields and calculates their effect on infections in the human population.
Researchers have found that even low concentrations of pesticides, including atrazine, glyphosate, and chlorpyrifos, can increase the transmission rate of schistosomiasis. In communities in the Senegal River Basin in West Africa, disease rates from agrochemical contamination were on a par with those from lead exposure, high dietary sodium and low physical activity.